Do your Homework
Get online and do some research before you go. You should be able to find maps, pricing & discount information, special event schedules, and parking information ahead of time. Being educated on the basics can help you get in and out smoothly, without any surprises or hang-ups. It's also a good way to find out what manufacturers will be represented and where their displays will be located.
Plan a Route
Exploring an auto show can be a bit tiring, so decide what you want to see the most and make sure you do that early. That way, by the time you're starting to get worn out, you've hopefully already seen your favorites. I would suggest eating before you start your journey through the show. It won't be as fun if you're hungry the whole time.
Keep it Simple
A car show will be the most fun and memorable if you go with friends. More isn't necessarily better though. I'd say a group of 3-4 is a good size. A group of 4 can check out most cars together - 2 up front, 2 in the back. Plus, any more than that and you'll either be waiting on each other or looking for each other the whole time. With a smaller group you can stick together and keep up a fairly good pace from beginning to end.
You're going to want to sit in as many cars as you can. It's pain to wait in line, get in and out of cars, fool with seats, steering wheels, and everything else if you've got too many accessories. Make sure you've got the essentials, and nothing more. I'll have my wallet, phone, keys, and probably a small camera. Purses and bags will get in the way, and you'll get tired of carrying them around. Sometimes I'll wear a coat in, but even that can be a hassle. Most places will have a coat check, I'd recommend it if you can spare a couple bucks. It can be tough to keep things simple with kids or a family, but a car show can also be a good place for little ones to use up some energy (which could result in a nice quiet ride home!)
As with any other activity involving a crowd, you're vulnerable to bullies and pick-pockets. This is another good reason to travel light. A purse, backpack, or shoulder bag is very inviting to a thief. Make sure to keep your kids within sight too. The atmosphere at an auto show is generally pretty positive and upbeat, so "strangers" can look quite harmless.
You'll almost always have to stand in line for your chance to sit in the more exotic or popular cars. This will be especially true of new models, or luxury vehicles. If you encounter a really long one, check out something else and come back later. The crowds will come and go in waves.Be StrategicIf your schedule will allow it, visit the show at an off-peak time. The weekends will usually be the most busy. From my experience, the last couple of days are usually the most crowded. This can take some fun out of the show.
Look for Free Stuff
Keep your eyes peeled for freebies. Typically you'll be able to find posters, key chains, etc. at some of the bigger shows. The earlier you go, the better chance you have of coming home with some loot. The good stuff will surely be gone long before the show moves on to the next city.
[Image credit: Nexeus Fatale, creative commons]